JACKSONVILLE, Fla. — Stick a pin almost anywhere on a map of Florida and you’ll find a legal battle over who will be eligible to vote in the coming presidential election — and when, and how, and where.

In a state crucial to Mitt Romney’s battle to replace President Obama, a law passed in 2011 by the Republican legislature and signed by Gov. Rick Scott (R) has created an awesome wake of litigation.

The law imposes more than 75 changes, including restrictions on who can register voters and limits on the time allowed for early voting. Sponsors of the measure said it creates a more reliable system that combats voter fraud, while opponents, a group that included every Democratic lawmaker, called it a partisan ploy to suppress voters who traditionally favor Democrats.

But unlike the frenzied trip to the U.S. Supreme Court that followed the close of voting in the 2000 presidential race, the Sunshine State’s legal battles are being waged in advance of the November vote.

“Florida is desperately trying not to be the next Florida,” said Richard L. Hasen, an expert on election law whose new book, “The Voting Wars,” begins with a chapter titled “All I Really Need to Know I Learned in Florida.”

There could be many contenders for the title this fall. In battleground states such as Ohio, Pennsylvania and Wisconsin, changes in voting laws have resulted in high-stakes legal battles over whose ballots will be counted.

One of the many legal battles in Florida was answered last week, when a panel of federal judges ruled that the new limits on early voting could not be implemented in five counties that receive special scrutiny under the Voting Rights Act. Florida, said the unanimous ruling, “has failed to satisfy its burden of proving that those changes will not have a retrogressive effect on minority voters.”

That will hardly be the last judicial decision affecting Florida’s nearly 11.5 million voters before polls close on Nov. 6.

In Miami, minority groups have sued the state over whether its plan to purge the voter lists of noncitizens might result in legitimate voters losing their rights.

In Tampa, a similar lawsuit asks whether the state’s plan to purge the lists violated a different section of the federal law.

In Tallahassee, judges in two courts considered a host of suits and countersuits, including one change that caused the League of Women Voters to suspend voter-registration efforts for fear of criminal penalties.

And here in Duval County, where African Americans make up a larger portion of voters than in any of Florida’s other large counties, Elder Lee E. Harris has joined a lawsuit that would require the state to continue to allow early voting on the Sunday before the election.

Harris said he devotes part of the Sunday worship service at Mount Olive Primitive Baptist Church to making sure each of the church’s approximately 280 worshipers is registered to vote. He hands out an 11-point checklist about voting eligibility.

On the Sunday before the election, church vans and church members with cars ferry those without transportation to county early-voting stations.

“Sunday in the African American community is traditionally our day of rest, and once that early voting — ‘take your souls to the polls’ — caught on here, it became easier for people to get involved in voting,” Harris said. “Early voting in the minority community paid off.”

Harris’s view is supported by a study done by University of Florida election-law specialist Daniel A. Smith, hired by Harris and other challengers to the limits on early voting, including U.S. Rep. Corrine Brown (D).

On the Sunday before the 2008 presidential election, Smith said, 43 percent of the early votes cast that day came from African Americans, even though they make up only 28 percent of the county’s electorate. In a 2011 mayoral contest, there were more black voters than white voters on the Sunday before the election, he said.

The 2011 law reduced the number of days that Florida’s 67 counties may offer early voting from 14 to eight and reduced the minimum number of hours polls must be open from 96 to 48. It did require for the first time that all counties offer Sunday voting — it was optional before — but specified that the Sunday could not be the one two days before the election.

Federal oversight

Five of Florida’s counties — the largest of which is Hillsborough, which includes Tampa — are covered by Section 5 of the Voting Rights Act because of a history of discrimination, requiring approval from federal authorities of election-law changes.

And a three-judge panel in Washington agreed Thursday that Florida could not prove the early-voting changes would not significantly cut back on black voter participation.

“This dramatic reduction in a form of voting disproportionately used by African-Americans would be analogous to (although certainly not the same as) closing polling places in dispropor­tionately African-American precincts,” said the opinion, written by U.S. Court of Appeals Judge Merrick B. Garland and District Judges Colleen Kollar-Kotelly and Ellen Segal Huvelle.

The judges said the changes might pass muster if the counties agree to the maximum number of hours allowed instead of the minimum.

If not, the panel’s decision sets up a scenario in which different counties might operate under different procedures. For instance, Tampa’s voters might continue to have 14 days of early voting while those on the other side of the bay in St. Petersburg would have only eight. The 49,000 voters in the Florida Keys could have the longer time, while Miami-Dade County’s 1.2 million would have the shorter.

Duval is not one of the counties affected by the decision.

Laws that differ by county

During the recount in the 2000 presidential election, the state told the Florida Supreme Court that it would be “inappropriate to apply different election laws to different counties within the state of Florida.”

But Scott has ordered Florida’s 62 other counties to follow the new law.

That, not surprisingly, is the subject of another lawsuit. Howard Simon, executive director of the American Civil Liberties Union of Florida, said Scott’s “insistence that the state go forward with two different sets of voting laws . . . is a recipe for chaos and another embarrassment for our state.”

The Scott administration points out that the vast majority of the law has received the federal government’s blessing, even though a federal judge in May struck much of the law’s restrictions on third-party voter registration as a violation of the First Amendment. State officials point out that early voting in the state’s 2012 primaries continued to show growth, even under the reduced hours.

Scott declined to be interviewed for this article, and press secretary Lane Wright said the governor was moving on to other endeavors. “We don’t really have anything more we want to say about it,” Wright said.

Citizenship and the DHS

But controversy in Florida is never over. The state reached an agreement last week to use the Department of Homeland Security’s database to again attempt to purge the state’s voter rolls of noncitizens.

The first effort did not go well. Scott’s secretary of state, Ken Detz­ner, originally came up with a list of more than 180,000 names, then cut that to 2,600 possibilities sent to the county supervisors of elections. But the list was quickly shown to be flawed — war veterans and longtime voters were quickly identified in press reports — and the effort was abandoned.

The Scott administration said the use of the Homeland Security database will make the new effort much more precise. But the Justice Department opposes the effort so close to the election, and two lawsuits are waiting.

Robert Barnes has been a Washington Post reporter and editor since 1987. He has covered the Supreme Court since November 2006.

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